Best way to put a grid on Ground Glass?

[eli griggs]

Grab a ruler and a .5 fine point pencil. Do it on the frosted side of course.

You can wash it off later, but it will stay on there for years and its free.

This is what I did with my speed graphic and it never needed redoing.

Yes,

At a guess, he meant an incra ruler.

Pardon my misspelled name.

I have several of these tools and while I misspell the name, they are a one of the first tools I reach for in the studio and workshop.

A 300mm/12" rule is a perfect line tool for a 8" x 10 gg, IMO.